The use of LEDs in general lighting is becoming more desirable. LED illumination devices sometimes use wavelength converting materials to generate a desired color point. The color conversion of light by wavelength converting materials, however, generates a significant amount of heat that will adversely affect the wavelength converting materials over time, e.g., degrading the color conversion performance and altering the color point of the light produced by the illumination device over time. Consequently, improvements to illumination device that uses light emitting diodes as the light source are desired.